UK compost
What compost for achillea ptarmica 'the pearl' in the UK?
Achillea ptarmica 'The Pearl'
More about achillea ptarmica 'the pearl' in the UK
Which compost achillea ptarmica 'the pearl' needs
For achillea ptarmica 'the pearl' the mix to buy is peat-free multipurpose compost. Adaptable to most garden soils, including heavier and moister ground than other Achillea, at neutral to slightly alkaline pH. Still needs reasonable drainage to avoid winter crown rot; it spreads more freely in fertile, moist soil.In British garden centres the bagged growing medium is sold simply as “compost” (multipurpose, ericaceous, or loam-based John Innes), which is a different thing from the rotted garden “compost” you make in a heap — for a pot you want the bagged kind.
Peat-free compost
Buy peat-free. The sale of peat compost to home gardeners is being phased out across the UK, and the RHS recommends peat-free on environmental grounds. A good peat-free multipurpose grows achillea ptarmica 'the pearl' perfectly well; the one habit to change is watering — peat-free dries faster at the surface while still moist below, so check by feel a knuckle deep rather than trusting the look of the top.
Ericaceous or multipurpose?
Achillea ptarmica 'The Pearl' is straightforward: an ordinary peat-free multipurpose compost is right. For a big specimen or a pot it will live in for years, mixing in some loam-based John Innes No.2 or No.3 adds weight and holds nutrients longer. Ericaceous compost is not needed unless a plant is specifically a lime-hater.
For the full recipe, pH and drainage detail (US wording), see the achillea ptarmica 'the pearl' soil & potting-mix guide.
Compost for Achillea ptarmica 'The Pearl' in the UK — frequently asked questions
What compost should I use for achillea ptarmica 'the pearl' in the UK?
Use peat-free multipurpose compost. Adaptable to most garden soils, including heavier and moister ground than other Achillea, at neutral to slightly alkaline pH. Still needs reasonable drainage to avoid winter crown rot; it spreads more freely in fertile, moist soil. In UK garden centres this is sold simply as "compost" — the bagged growing medium, not garden-made leaf-mould — so match the description above rather than a brand.
Can I use ordinary multipurpose compost for achillea ptarmica 'the pearl'?
Yes. A good peat-free multipurpose compost is exactly right for achillea ptarmica 'the pearl'. For a large or long-term pot you can mix in some John Innes No.2 or No.3 (loam-based) for extra weight and staying power.
Should the compost be peat-free?
Yes. Sales of peat compost to home gardeners are being phased out in the UK, and the RHS recommends peat-free for environmental reasons. Modern peat-free multipurpose composts grow achillea ptarmica 'the pearl' perfectly well — they dry a little faster at the surface, so check moisture by feel rather than by the look of the top.
Does achillea ptarmica 'the pearl' need grit or perlite added?
Not essential, but a couple of handfuls of perlite in the mix improves aeration and guards against overwatering — useful on a cool, damp British windowsill where compost stays wet longer.
What pot and drainage does achillea ptarmica 'the pearl' need?
Always a pot with drainage holes. Average to moisture-retentive, well-drained loam. Stand it on a saucer, empty any water that collects after watering, and never leave the pot sitting in a full outer cover — waterlogged compost in a cool UK room is the commonest cause of root rot.
More achillea ptarmica 'the pearl' care
See the full achillea ptarmica 'the pearl' care guide, its UK watering and UK hardiness.